The initial goal? "To find the right rock to begin doing contact science with the arm."

Once there, the rover can call on the most sophisticated suite of tools ever sent to an alien planet, including an x-ray spectrometer to identify elements in rocks, a supersharp close-up camera, and a lab-in-a-box that chemically analyzes samples dropped in by the arm.

The ultimate goal is to uncover—or rule out—the evidence of past or present organic compounds and other substances seen as building blocks of life as we know it.

Curiosity's likely next stop is a site called Glenelg, chosen in part because it features three types of rock. But "the real prize" is 18,000-foot (5,500-meter) Mount Sharp, some 4 miles (6.4 kilometers) away, writes Marc Kaufman in his National Geographic e-book Mars Landing 2012, excerpted below.

There, in the center of Gale Crater, "many layers of rock are clearly exposed, allowing for an entirely unprecedented examination and reading of the planet's past."

Named after former NASA planetary scientist Robert Sharp, it is known to have lots of minerals at its base and many layers of rock to study.

Scientists want to understand how towering Mount Sharp came to be in the middle of a crater. The mountain doesn't seem to have a volcanic history, leading some to theorize it was carved out of the crater by powerful, circular winds.

However it came to be, the mountain offers the best look ever at the geology of Mars. Gale Crater is known to be more than three billion years old, and so Mount Sharp is expected to have a geological history—present in the layering and composition of different kinds of rock—going back that far.

If all goes well, the rover will intensely examine the mountain base and then continue to climb up its sloping valleys during its functional life. Curiosity will examine exposed geological layers never seen before and analyze their contents. It will be quite literally a field day for geologists, though at a many-million-mile remove.

The mission calls for Curiosity to be roving, sampling, analyzing, and sending back images for two years. With a power source that can supply electricity far longer than two years, though—as well as a history of Mars rovers lasting years longer than their expected life span—there's a good chance that a healthy Curiosity could make it far higher, even to the top of Mount Sharp. The limiting factor would be NASA funding, which is in increasingly short supply.

The journey of Curiosity will unquestionably be an odyssey of surprises, discoveries, and difficulties. ...

[NASA software developer and Curiosity driver John] Wright, who helped remotely drive the Mars rover Spirit, said that directing Curiosity "is at least ten times more complicated." This is a function of its size, its science payload, the terrain it will travel, and the fact that it can make more than 4,000 unique maneuvers.

Its path and the timing of its moves will be largely written in code sent to the rover from Earth at the beginning of each Mars day, but Curiosity presents another unique challenge: The rover can make many more decisions on its own than past models and so requires a different and far more intense kind of oversight.

In this sense, Curiosity is more of a self-controlling robot than past rovers, although the MSL team is clear in saying it does not have artificial intelligence per se.

While Spirit and Opportunity could also make some limited decisions on their own about which path to take to avoid an obstacle, that information was lost to the rovers as soon as they made their moves. Curiosity will be more capable of guiding itself and will also keep track of everything it has done and where it has gone.

As Wright explained it, this new capability for storing Curiosity's decision-making onboard requires his team not only to know where the robot-rover has been but also to understand where "the rover thinks it drove."

"The people who designed and built the software tried to make it easy to use," he said. "The way they did that was to make the rover smarter and more aware, to remember more things so it could respond on its own. We wouldn't have to specify everything.

"But for us, that means we have to know everything that the rover knows. It's possible that Curiosity could think it is in a different place than we know it to be, and that could cause some problems. So we have to know, in a sense, what it's thinking.

"This is a brand-new world for all of us. We have to know what it knows. And when it gets really, really smart, we need to know what it will do."

This is where the R2-D2, C-3PO, and WALL-E qualities of the Curiosity persona begin coming into focus. Nobody at JPL has any illusions that Curiosity is anything but a roving robot, but it's nonetheless not unusual to hear scientists and engineers talk about what "he" will do in particular circumstances.

There's a certain pride (along with wariness) about Curiosity's increased knowledge, and there's an unspoken but undeniable sense of the rover as brave and heroic.

This is really not unexpected: The previous, surprisingly long-lived Mars rovers Spirit and Opportunity became famous worldwide as the "little rovers that could"—plucky fellows that far exceeded human expectations.

As Curiosity makes its Martian trek—and especially when it starts climbing Mount Sharp—it would be surprising if a similar kind of emotional attachment didn't develop with the NASA team and the public at large. The rover is a machine, but that doesn't mean it can't have personality, too.